The invention is directed to a retractable double trailing axle attachment that is adapted to be mounted on an extended frame of a tandem axle dump truck although the attachment can be utilized with a variety of different vehicles. The retractable double trailing axle attachment permits an increase in the legal load carrying capacity of the associated dump truck by adding more axles thereto while still maintaining the maneuverability during running conditions while providing the convenience of raising or retracting the axles up out of the way in a nonrunning/dumping position for dumping directly behind the dump truck. The latter is essential in order to dump such materials as hot mixed asphalt into a paving machine. Thus, with the present retractable double trailing axle attachment a total of two more axles are provided immediately at the rear of the dump truck adjacent the tandem axles thereof resulting in a total of seven axles within thirty four feet. In Texas, and possibly other states, this allows a tandem axle dump truck to haul 80,000 lbs., the maximum allowable load on any Texas highway. Accordingly, a higher legal pay load and attendant convenience is achieved by the retractable double trailing axle attachment of the present invention.